Cacao polyphenol extract suppresses transformation of an aryl hydrocarbon receptor in C57BL/6 mice

Dioxins enter the body through the diet and cause various toxicological effects through transformation of an aryl hydrocarbon receptor (AhR). Plant extracts and phytochemicals including flavonoids are reported to suppress this transformation. This paper investigates the suppression by a cacao polyphenol extract (CPE) of AhR transformation in vivo. The CPE was administered orally to C57BL/6 mice at 100 mg/kg of body weight, followed 1 h later by 3-methylcholanthrene (MC), an AhR agonist, injected intraperitoneally at 10 mg/kg of body weight. CPE suppressed the MC-induced transformation to the control level by inhibiting the formation of a heterodimer between AhR and an aryl hydrocarbon receptor nuclear translocator in the liver at 3 h postadministration. It also suppressed MC-induced cytochrome P4501A1 expression and NAD(P)H:quinone-oxidoreductase activity, whereas it increased glutathione S-transferase activity at 25 h. CPE constituents and their metabolites might contribute, at least in part, to the suppression of AhR transformation. The results indicate that the intake of CPE suppressed the toxicological effects of dioxins in the body.     

Changes in peripheral leukocyte populations of weak calf syndrome of Japanese black calves

To clarify the cellular immune condition in Japanese Black (JB) calves with a weak syndrome, peripheral leukocyte populations were analyzed by flow cytometry. Twenty JB calves were divided into two groups based on clinical observations; one group of calves was weak, because they had experienced an onset of diarrhea within 3 days after birth and needed treatment (Group 1 ;n=10), and the other group of calves was healthy (Group 2; n=10). With regard to leukocyte populations, CD8(+) cells and gamma delta T cells in Group 1 were markedly lower than those in Group 2 during the experimental periods. It is possible that immune-insufficiency might be based on T lymphocyte function in weak syndrome JB calves during the growth process.     

Flow cytometric analysis of peripheral blood mononuclear cells induced by experimental endotoxemia in horse

Cellular activation and functional cell surface markers were evaluated during experimentally-induced endotoxemia in healthy horses. Eight healthy adult horses were infused a low dose of endotoxin (lipopolysaccharide from Escherichia coli O26: B6, 30 ng/kg of body weight, IV) and five control horses were given an equivalent volume of sterile saline solution. Venous blood samples were collected for flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) and to measure plasma endotoxin concentrations. Clinical signs of endotoxemia were recorded at 10, 20, 30, 40, 50 min, 1, 2, 3, 4, 8, 16, 24 and 48 hr after endotoxin or saline solution administration. Clinical findings characteristic of endotoxemia (tachycardia, tachypnea, increased rectal temperature, and leukopenia) occurred transiently in all horses administered endotoxin; however, plasma endotoxin concentrations were detectable in only 50% (4/8) of the endotoxin-infused horses. The percentage of CD4(+), CD5(+), and CD8(+) cells decreased while the percentage of CD14(+), IgM(+), and MHC class II(+) cells increased significantly after endotoxin infusion. Alterations in the immunophenotype of PBMCs from horses with experimentally-induced endotoxemia were associated with changes in vital signs, indicating that endotoxin altered the immuno balance.     

Inflammatory cytokines and antigen-responsive mononuclear cells in peripheral blood of cattle infected with Salmonella takoradi

To determine the immunological response in lactating dairy cows infected with Salmonella (S.) Takoradi, the relationships among distributions of peripheral blood mononuclear cell (PBMC) subpopulations, endotoxin concentrations and dynamics of inflammatory cytokines in blood were investigated. The ratio of CD4+ T cells to CD8+ T cells was significantly lower in the affected cattle than in the control cattle (p<0.05) to decrease in the number of CD4+ T cells in the infected cattle. In contrast, the numbers of gammadeltaT cells, MHC class II-positive cells were significantly higher in the affected cattle than in the control cattle (p<0.01 respectively). Endotoxemia was found in all but one of the affected cattle. Serum IL-1 and IL-6 bioactivities were significantly higher in the affected cattle than in the control cattle (IL-1, p<0.05; IL-6. p<0.01). Serum TNF-alpha activities and levels were not detected in the control and affected cattle. The activities of proinflammatory cytokines determined by the bioassay are important to the relationships between concentration of endotoxin, cytokines and clinical signs. such as leukocytosis, leukopenia, fever or bacterial shedding. Serum IL-2 levels were lower in the affected cattle than in the control cattle. Serum IFN-y was not detected in the affected cattle except one. These results by the ELISA seemed to reflect the condition of subpopulation in the PBMCs from the shedding cattle. The present results suggest that cellular immunity is suppressed while the humoral immunity is activated in acute bovine salmonellosis.     

Effects of epidermal growth factor on placental amino acids uptake in pregnant rats

To evaluate the effects of epidermal growth factor (EGF) on placental amino acids uptake, transport activities for L-proline, L-leucine, and L-alanine were kinetically examined in placental microvillous vesicles(PMV) obtained from pregnant rats administered with EGF(100 and 200 microg/kg/day) from day 18 to 21 of pregnancy. The Vmax of Na(+)-dependent proline uptake remarkably increased with a dose-dependent manner of EGF, while Km did not change. In contrast, Vmax and Km values of Na(+)-dependent and -independent alanine, and Na(+)-independent leucine uptake were not affected. These results suggested that EGF enhanced proline transport activity in placental microvillous membranes, resulting in an increase of proline concentration in the fetal blood. The selective up-regulation of proline uptake was considered to contribute to fetal growth by EGF.     

CPPU application on size and quality of hardy kiwifruit

For the purpose of determining the appropriate conditions of application to increase the size of a hardy kiwifruit, Actinidia arguta ‘Mitsuko’, N₁-(2-chloro-4-pyridyl)-N₃-phenylurea (CPPU) was applied at three different growth stages of the crop: at petal fall, 10 and 25 days after petal fall (DAPF), and three different concentrations: 1, 5 and 10 mg l⁻¹. A significant increase in fruit size was obtained by treatment at the concentrations of 5–10 mg l⁻¹ and at 10 DAPF. The fruit weight doubled. Although a significant reduction in the concentrations of total soluble solids (TSS), titratable acids (TA) and ascorbic acid (AsA) in the CPPU-treated fruits was recorded, the TSS/TA ratio and AsA content per fruit increased by the treatment. CPPU application at petal fall induced abnormally protruding fruit tip.     

Transmission of mitochondrial plasmids in protoplast cell fusion between compatible monokaryons of <Emphasis Type="Italic">Lentinula edodes</Emphasis>

Electrophoretic analysis of the transmission pattern of mitochondrial plasmids in protoplast cell fusion between compatible monokaryons of Lentinula edodes indicates that three of the four plasmids carried in parental monokaryons are effectively transferred and replicated in the protoplast fusants. The two monokaryons, 1158a and 1569a, carried different plasmids that could be distinguished by a single restriction digest. Electrophoresis of intact plasmids and restriction analyses indicate that all but one of the fusants carry three of the four possible plasmids, indicating that transmission of plasmids in protoplast fusions is principally biparental in L. edodes. Thus, heterocytoplasmic cells of L. edodes can be effectively constructed by protoplast cell fusion. In addition, plasmids of the same homology group cannot coexist in the heteroplasmic cells after protoplast cell fusion. Contribution No. 382 of the Tottori Mycological Institute     

Autoantibodies against glial fibrillary acidic protein (GFAP) in cerebrospinal fluids from Pug dogs with necrotizing meningoencephalitis

Cerebrospinal fluids (CSFs) from 9 Pug dogs with necrotizing meningoencephalitis (NME: Pug dog encephalitis) were examined to identify the antigens for anti-astrocyte autoantibodies. Each CSF exhibited a positive reaction to the cytoplasm of cultured canine astrocytes by an indirect fluorescent antibody test. In an immunoblotting analysis on normal canine brain proteins, eight of 9 CSFs showed a common band of 52 kDa, corresponding to glial fibrillary acidic protein (GFAP), and all of 9 CSFs reacted with purified bovine GFAP. From these results, GFAP is one of the common autoantigens in Pug dogs with NME. On the other hand, the reactivity of CSFs to chymotrypsin-digested bovine GFAP fragments were variable among dogs, indicating that the antibodies in the CSFs recognized different epitopes on GFAP.